1. Field of the Invention
This invention relates to a device for guiding a wire harness of a steering column having a tilt function and a telescopic function.
2. Description of the Related Art
In the wire harness installed in this kind of steering column, in order to respond to operations of a tilting mechanism and a telescopic mechanism of the steering column, it is necessary that the wire harness is so constructed as to absorb its expansion and contraction derived from the respective operations of mechanisms.
In Japanese Unexamined Utility Model Publication (Kokai) No.63-32527, there is disclosed a device to absorb the expansion and contraction of wire harness.
This device is provided under a steering column with a harness pool to accommodate the middle part of the wire harness so as to be a loop, whereby it is possible to shrink or enlarge a diameter of the loop by a telescopic action of the steering column. Arranged in the harness pool is a boss which comes into contact with the harness loop from an inside thereof. The loop is adapted so as to be shrunk and enlarged as a base point of its contact with the boss.
Further, in Japanese Unexamined Patent Publication (Kokai) No.3-7639, there is also disclosed another device to have the same functions as mentioned above.
In this device, a protector for accommodating the wire harness comprises two members which engage with each other. By the arrangement, the protector can deform easily in the longitudinal direction thereof. The members are provided with harness guards to divide the wire harness W therein into two harness parts, in a direction of width thereof. In operation, since the harnessguides can deform along the width direction of the wire harness, accommodating the divided wire harness therein, it is possible to absorb the expansion and contraction of wire harness itself.
However, the former device has a shortcoming such that, since the harness loop is adapted so as to be shrunk and enlarged as a base point of its contact with the boss, a stress is produced at the contact, particularly, when the loop is shrunk.
On the other hand, the latter divice has also a shortcoming such that, since the protector is formed to be bifurcated, the device itself is apt to be large-sized. In addition, in the device, there is a possibility that the forked harness parts are idle in the protector thereby to make a noise.